Help cant install bootmii and homebrew

um hi my problem is that i have a wii and was following the New 3.1-4.1 Softmod for ANY Wii but when i put my sd card in and tried to install bootmii it just told me that i had the bootmii installed and to suck it. i hvae no homebrew or anything. my wii is a 4.0U i think korean wii and dont know what to do to play games i dloaded like isos and the backups and other things alike on my wii. do i format it or use a diff tool ,plz tell me.really confused dont wanna buy a new wii